Lung cancer has become a problem with major public health significance in women. Although tobacco smoking is the most important risk factor of lung cancer, there is still much of the variation in risk that is not fully explained by smoking. Furthe, although there has been considerable investigation of prognostic factors of lung cancer, our knowledge on factors related to lung cancer survival is still evolving. Osteoporosis is a common disease in aged population with the majority of cases occurring in postmenopausal women. Bisphosphonates, inhibitors of osteoclast-mediated bone resorption, are commonly used in the management of osteoporosis. Experimental studies have shown the anti-cancer properties of bisphosphonates; however, only a few recent epidemiological studies investigated the potential impact of bisphosphonate use on the development and/or progression of cancers, including breast and colorectal cancer. Very limited studies have been conducted to evaluate bisphosphonate use in relation to lung cancer incidence and mortality in older women. Utilizing an existing prospective cohort study of postmenopausal women, the proposed study will investigate relationships between oral bisphosphonate use and lung cancer risk, as well as the association of bisphosphonate use prior to cancer diagnosis with lung cancer survival among postmenopausal women. Results from the proposed study have the potential to provide very important information for understanding how personal use of oral bisphosphonate for another indication might impact on lung cancer development and progression in older women, as well as to improve our understanding about etiology of lung cancer and prognostic factors of lung cancer in women. These understandings would provide first-step data for further intervention trials or investigations of molecular mechanisms of bisphosphonate and lung cancer progression. More importantly, these understandings would have major public health implications for improving lung cancer survival in older women.